Portable information apparatuses, such as notebook personal computers, are often coupled with networks, such as the Internet, via wireless local area networks (LANs) since having their portability. The notebook personal computers are often coupled with external devices not via cable communications, such as USB or IEEE1394, but via wireless communications, such as IEEE802.11b or Blue tooth.
FIG. 3A is a perspective view of notebook personal computer 1051, a conventional information-processing apparatus. Notebook personal computer 1051 includes main body 1011 of the notebook personal computer and antennas 1013, 1031, and 1032 for wireless communications.
Antenna 1013 is a whip antenna (a vertical antenna) for a wireless communication under a standard of a digital portable phone, and enables notebook personal computer 1051 to receive the same service as internet-connecting services provided for portable phones.
Antenna 1031 is applicable to the IEEE802.11b standard, a standard of wireless LANs. Antenna 1032 is applicable to the Bluetooth, which is standardized for wireless communications with portable information devices.
FIG. 3B is a top view of antennas 1031 and 1032. Each of antennas 1031 and 1032 is made of a printed wiring board including copper foil 1033A printed on insulation body 1033B. The antennas have simple structures for receiving or sending high frequency signals with cable 1034 connected with copper foil 1033A, and mounted in main body 1011, thus often being invisible from outside.
Antenna 1013 for a portable phone can be accommodated in personal computer 1051, while the antenna is visible from the outside of personal computer 1051 similarly to general portable phones.
As shown in FIG. 3A, antenna 1013, antenna 1031, and a high frequency circuit connected to them are arranged over display 1055 of main body 1011 for preventing human bodies from influences of the device emitting electromagnetic waves. The antennas are arranged for allowing notebook personal computer 1051 to be used not only on a desk but also on a lap. Antenna 1032 treats electromagnetic waves weaker than electromagnetic waves for a portable phone and a wireless LAN, and is accordingly arranged at an end of main body 1011.
In regard to devices emitting electromagnetic waves to human bodies, according to the growth of the market of portable phones, a standard of electromagnetic waves permissible for human bodies has been determined as a specific absorption rate (SAR).
The IEEE802.11b standard is a standard of a wireless LAN which performs wireless communications at about 11 Mbps in a 2.4 GHz band. The Bluetooth, a standard of wireless communications for portable information devices, enables communication at 1 Mbps with radio waves in a 2.45 GHz band. Both of them are communication standards certified world-wide.
Global System for Mobile Communications (GSM) of portable phones including GSM 900 using a 900 MHz band in Europe and Asia, GSM 1800 using a 1800 MHz band in Germany, the UK, France, Hong Kong, Singapore, and Taiwan, and GSM 1900 using a 1900 MHz band in the U.S., Canada, and Hawaii is well known. The GPRS system, which has a communication speed of maximum 115 kbps using a portable phone network of the GSM, is also known.
The EDGE system, a system based on the GSM system and a technology succeeding the GPRS system, is known besides the GSM system and the GPRS system. Furthermore, new standards, such as CDMA, have been developed.
Accordingly, antenna 1013 and the high frequency circuit corresponding to each of the portable phone standards are preferably unitarily packaged and are selected by manufacturers based on respective specifications or destinations of notebook personal computers.
However, there are some problems for antenna 1013 and the high frequency circuit packaged and mounted separately from main body 1011 mechanically, electrically, and thermally. In the portable phone standard which requires predetermined receiving characteristics in wide ranges, antenna 1013 is required to have a high efficiency for taking weak radio waves into the high frequency circuit efficiently. Main body 1011 itself may block radio waves depending upon the arrangement of antenna 1013 or the process of mounting a package. Besides, a performance of antenna 1013 may deteriorate if a case of main body 1011 is close to antenna 1013 or if an environmental obstacle, such as a body of a user, is close to antenna 1013.
In addition, the high frequency circuit is often implemented by integrated circuits having high powers and operating at high frequencies, thus generating a lot of heat. The packaged high frequency circuit is isolated from main body 1011 thermally, hence confining the heat to the package. Accordingly, it is necessary that the package itself dissipates the heat, or the package transfers the heat to main body 1011 to dissipate the heat.